Field of the Invention
The present invention concerns the interfaces between a user and a computer system, in particular in the field of games, and more particularly a method and devices for interfacing a plurality of mobile devices with a computer system.
Description of the Related Art
In numerous situations, it may be necessary, for a computer system, to detect the position and/or the orientation of mobile entities to enable the latter to react accordingly. Thus, for example, in a game of chess enabling a user to play against a virtual user simulated by the computer system, the application implemented on the computer system must know the position of all the pieces of the chess board, in particular those moved by the user, to compute its move.
There are solutions for detecting the position and/or the orientation of real objects on a game board making it possible to use those objects as an interface for a computer system.
Thus, for example, resistive type touch screens may be used as a board game in order to detect the position of an object such as a stylus when sufficient pressure is applied. However, this type of screen in general only supports a single contact and requires constant pressure by the user to know the position. In other words, it is not possible to detect the position of the stylus if the pressure applied by the latter is relaxed.
It is also possible to use capacitive type touch screens, based on the principle of a leakage of current through a conductive body. However, only objects that are conductive and linked to a ground enable the detection of their position. Thus, for example, the positions of objects of plastic or wood cannot be determined using such screens.
Moreover, in general terms, the solutions based on touch screens or touch film, only support a limited number of simultaneous or almost simultaneous contacts and do not enable the determination of a high number of objects.
Other solutions implement technologies based on infrared, in particular in the form of tables. Thus, for example, the products known under the names Surface (Surface is a trademark of Microsoft), mTouch (mTouch is a trademark of Merel Technologies) and Entertaible (Entertaible is a trademark of Philips) use infrared cameras disposed within the thickness of the table. However, the required thickness of these tables makes them bulky and of low mobility and gives them a certain rigidity. Furthermore, their price does not really allow for family use.
Lastly, these solutions do not enable detection of the altitude, relative to a predetermined reference, of the mobile entities of which the movements and/or orientations are detected.
In document WO 2012/028827 a method has been provided to enable a computer system to simply and efficiently determine the position of a high number of mobile devices which may be used to interact with that computer system. A method of assisting location of mobile devices has also been described in French patent application FR 1255334.